Examples include AmLactin

http://classyfire.wishartlab.com/tax_nodes/C0000000
http://classyfire.wishartlab.com/tax_nodes/C0000264
http://classyfire.wishartlab.com/tax_nodes/C0000472
http://classyfire.wishartlab.com/tax_nodes/C0001359
http://classyfire.wishartlab.com/tax_nodes/C0001359
http://classyfire.wishartlab.com/tax_nodes/C0001661
http://classyfire.wishartlab.com/tax_nodes/C0001137
http://classyfire.wishartlab.com/tax_nodes/C0001205
http://classyfire.wishartlab.com/tax_nodes/C0003940
http://classyfire.wishartlab.com/tax_nodes/C0004150
http://classyfire.wishartlab.com/tax_nodes/C0001831
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:78320
http://www.hmdb.ca/metabolites/HMDB0144295
http://www.genome.jp/dbget-bin/www_bget?drug:D00111
http://www.genome.jp/dbget-bin/www_bget?cpd:C01432
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=612
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46505582
https://www.chemspider.com/Chemical-Structure.592.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=23233
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=1314409
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=78320
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL1200559
http://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=2934
https://www.drugs.com/cdi/lactic-acid-cream.html
https://en.wikipedia.org/wiki/Lactic_acid